The surface treatment or coating using vacuum deposition is now being used as one method for generating high-quality products or products for specific uses in the field of the semiconductor industry, the display industry, the information and electronic industry, the solar-related industry, or the IT components industry.
Specifically, such vacuum deposition may be applicable regardless of the kind of substance to be deposited such as a metal, a plastic, or glass. However, since most of deposition processes are performed under high-vacuum atmosphere, there are limitations in that it takes a long time to perform processes, and an evaporation source is excessively consumed by the deposition process.
When a surface of a plastic film or a strip coil is treated, it is difficult to perform the vacuum process (deposition) intermittently, due to a production rate and a continuous characteristic of the object to be deposited. Accordingly, although a vacuum-to-vacuum process in which a plastic film or a strip coil is inserted into a vacuum chamber for a deposition process to be performed thereon under vacuum exists, there is a limitation that productivity is reduced because the strip coil on which the surface coating is completed should be replaced with a strip coil prepared for treating. Thus, this should not be called a continuous process in the true sense of the word. Also, there is a limitation that the products on which the surface treatment is completed are expensive in terms of manufacturing costs.
Thus, research into a process in which a strip wound under an outer atmosphere passes through a chamber in which a vacuum is continuously maintained using a sealing mechanism without losing vacuum pressure from the vacuum chamber to perform a continuous vacuum-deposition process, and then the strip on which the deposition process is completed is rewound under the outer atmosphere is being actively conducted.
For example, a strip passing apparatus, which guides a continuous passing of a strip to allow the strip to continuously pass through the vacuum chamber in a sealed state without losing vacuum pressure, is the most important technical aspect of a process for treating a surface of a strip.
Some such sealing apparatuses or mechanisms, in which a strip continuously (in a high speed manner) passes from an outer atmosphere to a vacuum (space), while maintaining the vacuum state, are known.
According to most conventional known sealing apparatuses or mechanisms, a strip is sealed under a vacuum using a sealing roll, a casing structure, or a structure in which the sealing roll and the casing have a multistage arrangement. However, since these apparatuses or mechanisms do not adequately deal with variations in a thickness or width of the strip, there are limitations in that it is difficult to treat a surface of continuously proceeding strips having various standards (widths).
Also, since the actual sealing of the strip is incomplete, a vacuum pumping performance within a chamber should be increased or be at least continuously maintained to maintain the vacuum state. Thus, when the apparatuses or mechanisms are operated, excessive processing costs are required. Therefore, the conventional known sealing apparatuses or mechanisms are uneconomical.
Alternatively, although a flow-resistance type sealing mechanism that has a multiple-division structure to increase air flow resistance is known, the sealing efficiency between an actually atmospheric-pressure space and a differential pressure space may be low. In this case, there is a limitation in that vacuum pumping should be continuously maintained.
In addition, provided is a conventional sealing mechanism of a different type (having a different configuration) in which a plurality of sealing rolls are disposed to have a multistage arrangement and a zigzag shape to maintain the sealing of a passing strip. However, in this case, it is difficult to adequately deal with variations in a width of a strip, as well as to manufacture an apparatus or mechanism having a precise structure for realizing an extremely narrow gap between sealing mechanisms to maintain sealing. Thus, in a case in which the apparatus or mechanism is applied to an actual manufacturing line, the cost burden may be increased, maintenance and repairs are difficult, and sealing is insufficient.
Thus, most of the various sealing apparatuses or mechanisms described above have a structure in which it is difficult to smoothly deal with a thickness or width of the strip. In particular, since strong vacuum pumping is, on the whole, required to maintain a vacuum state, there are limitations in that uneconomical energy consumption is significantly increased, and also, the actual effectiveness of the majority of the various sealing apparatuses or mechanisms described above is lower when it is applied to an actual manufacturing line.
An aspect of the present invention provides a strip passing apparatus, which can realize a tight seal around a proceeding strip and can seal or mask the strip according to an air-particle flow pressure among an atmospheric-pressure space, a differential pressure space, and a vacuum space to allow adequate sealing of the strip, thereby stably performing surface treatment of the strip under a vacuum, an apparatus for treating the strip with the same, and a method for treating a surface of the strip.